# Standardized Demographic Effects

## Interpretation Guide

Z₁ has a total SD of 1.37, but the within-country SD is only 0.27 (demographic change is slow). The between-country SD (1.34) accounts for 98% of total variation. Effects should be interpreted using the within-country SD for the FE specification and the total SD for the pooled specification, but the within-country magnitude is more relevant for policy interpretation (what happens as a country ages).

Rating scale: 1 (D) to 21 (AAA). Mean = 15.1, SD = 5.0.

## Standardized Effects (Within-Country SD)

| Model | 1 within-SD of Z₁ | Standardized beta | N |
|---|---|---|---|
| Rating baseline (pooled) | +3.9 notches | 0.78 SD of rating | 2,087 |
| Rating + debt controls (pooled) | +4.3 notches | 0.86 SD of rating | 2,048 |
| Rating (country + year FE) | +3.1 notches | 0.61 SD of rating | 2,048 |

## Standardized Effects (Total SD, Cross-Sectional)

| Model | 1 total-SD of Z₁ | Note |
|---|---|---|
| Rating baseline | +19.8 notches | Cross-sectional; not a plausible marginal effect |
| Rating + debt | +21.8 notches | Cross-sectional; dominated by between-country variation |

Note: The large total-SD effects reflect the strong cross-sectional correlation between aging and development/institutional quality. The within-country effects (3--4 notches per within-SD of Z₁) are the appropriate basis for interpreting how aging within a country over time affects its rating.
